WHITTIER – Police arrested a Whittier man Friday on suspicion of stabbing another man after a fight broke out on a bus, authorities said.

Ralph Portugal, 45, was booked on suspicion of assault with a deadly weapon, Whittier police Lt. Carlos Solorza said. The wounded man, a 21-year-old Whittier resident, was taken to a hospital with wounds that were not initially believed to be life-threatening.

Portugal and the alleged victim became involved in an argument for unknown reasons about 11:20 a.m. while both were passengers on a Montebello Transit bus in front of Whittier College, the lieutenant said.

The argument escalated into a fight, and Portugal pulled a pocket knife with a 4-inch blade, Solorza said.

Police said he then stabbed the victim several times in the chest.

Solorza said the wounded man continued to fight his attacker outside the bus before the two parted ways.

Officers responding to multiple 9-1-1 calls reporting the stabbing found the wounded man walking nearby, and Portugal was located near Penn Street and Comstock Avenue, Solorza said. Portugal had a bloody knife in his possession.